Starch-based release modifying excipients and pharmaceutical compositions derived therefrom

ABSTRACT

There is provide an extended release dosage form comprising a release modifying excipient comprising high amylose starch, cross-linked hydroxypropylated amylopectin, and a pre-gelatinized common starch; wherein the release modifying excipient is substantially free of crosslinks between amylose and amylopectin and substantially free of crosslinks between amylose and amylose. It has been found that the extended release properties of conventional cross-linked high amylose starches (e.g., Contramid®) can be reproduced by intimately mixing i) cross-linked chemically modified amylopectin; ii) a high amylose, non-chemically modified starch and; iii) a pre-gelatinized common starch. Producing a release modifying excipient in this way means that no chemical cross linking between (a) amylose and amylopectin or (b) amylose and amylose has occurred—properties heretofore considered vital for Contramid® function. The release modifying excipient blends overcome problems associated with use of Contramid, and provide a flexible platform for formulation of active pharmaceutical ingredients for controlled release applications.

RELATED APPLICATIONS

This application is a continuation of U.S. Pat. No. 16/477,028, filedJul. 10, 2019, which is a National Phase Entry of PCT/CA2018/051279filed Oct. 11, 2018, which claims the benefit of priority of U.S.Provisional Application No. 62/572,037 entitled “STARCH-BASED RELEASEMODIFYING EXCIPIENTS AND PHARMACEUTICAL COMPOSITIONS DERIVED THEREFROM”and filed Oct. 13, 2017; and of UK Application No. 1716965 entitled“STARCH-BASED RELEASE MODIFYING EXCIPIENTS AND PHARMACEUTICALCOMPOSITIONS DERIVED THEREFROM” and filed Oct. 16, 2017. Theseapplications are herein incorporated by reference in their entireties.

FIELD

The present disclosure relates generally to release modifying excipientsfor delivery of an active pharmaceutical ingredient (API). Moreparticularly, the present disclosure relates to dosage forms comprisinga starch-based release modifying excipient.

BACKGROUND

Conventional pharmaceutical dosage forms must often be taken four to sixtimes per day if efficacy is to be maintained. Extended releasepharmaceutical dosage forms (ER DFs) that must be taken only once ortwice a day are valuable as they are more convenient for patients to usethan conventional forms. While they can also reduce side effects, ER DFsalso promote dosing compliance, i.e., the likelihood patients willremember to take their dosage forms on time.

ER DFs are valuable for delivery of almost all active pharmaceuticalingredients (API) but are especially beneficial for pain medicationswhere failure to adhere to a dosing regimen can lead to breakthroughpain and, thereby, the chance that patients will overmedicate tocompensate for missed doses. This can lead to dangerous adverse events.Similarly, ER DFs are highly valuable for CNS drugs such asantidepressants where it is well known that patients are poorlycompliant, resulting in under medication and a recurrence of symptoms.

Starch-based excipient technology is used in the formulation of APIs fordrug delivery to individuals in need thereof, and is especially usefulfor formulation of ER DFs. In particular, it is used in matrix type drugdelivery systems wherein an API is blended with a modified starchexcipient followed by compression into a dosage form.

Upon ingestion of the dosage form, the gelling properties of thestarch-based excipients are thought to create a barrier to immediaterelease of the API in the gastrointestinal environment. Consequently,the period of time over which the API is released to enter thebloodstream is extended and the effects of the API are therebyprolonged.

Starch-based excipients for pharmaceutical use include cross-linked highamylose starches (CLHAS). These starches, comprising cross linked andchemically modified amylopectin and amylose subunits, are derived fromhigh amylose starches (HAS) extracted from low-cost, high-abundance farmcrops including corn, potato or pea crops. The gelling properties ofCLHAS vary according to the HAS of the variety of plant from which theyare is derived as well as natural variation within the plant species.HAS from corn varieties with very high amylopectin content (waxystarches) are known to generate more viscous gels when added to waterthan modified starches derived from low amylopectin varieties (commonstarches). HAS gel viscosity affects the release modifying properties ofthe derived CLHAS

To date, only corn-derived HAS have been used to manufacture CLHAS forthe development of ER DF on a commercial scale. To generate theirrelease modifying properties these starches must first be chemicallymodified. Starch modification comprises two steps, namely, cross linkingand side chain modification.

Cross linking is believed to add structural rigidity to the HAS and tolimit over swelling in the presence of water. Crossing linking resultsin covalent bonding between the amylose and amylopectin, amylose andamylose and amylopectin and amylopectin subunits of the HAS. The starchside chains are then treated with modifying agents including propyleneoxide, which introduces hydroxypropyl groups to a limited number ofcarbohydrate units on both amylose and amylopectin. This modification isintended to limit crystallinity and increase swelling. Finally, afteradditional washing steps, the cross-linked hydroxypropylated starch iswashed, heat treated and then spray dried. It is well known that thefunctionality of the CLHAS produced by chemical modification can behighly dependent on the exact manufacturing process used. Examples ofCLHAS that may be used in ER dosage forms are CLHAS developed by RougierInc. Canada and Labopharm Inc. Canada where the CLHAS is also known asContramid®.

Although CLHAS are valuable for drug delivery, the technology remainschallenging, for example due to one or more of: batch-to-batchinconsistency; an inability to optimize the amylose to amylopectinratio; and limited supply.

First, because HAS is derived from natural sources, there isbatch-to-batch inconsistency with seasonal and annual variations in theratio of amylose to amylopectin. This can result in inconsistent gellingspeeds between batches and therefore inconsistent effectiveness inpharmaceutical applications, particularly in large scale commercialproduction.

Second, the viscosity of HAS cannot be optimized for any particular API.While natural variation between corn varieties in the ratio of amyloseto amylopectin can be exploited to enhance ER delivery, it is notcurrently possible to synthesize HAS containing an optimized ratio forany particular API on-demand or at a commercial scale.

Third, the number of suppliers of CLHAS for pharmaceutical applicationsis limited. Therefore, pharmaceutical compositions containing excipientsfor matrix systems for ER delivery are vulnerable to a single point offailure. This could have detrimental consequences for individualsrelying on effective, long-acting formulations.

It is, therefore, desirable to provide an alternative to conventionalCLHAS.

SUMMARY

It is an object of the present disclosure to obviate or mitigate atleast one disadvantage of previous approaches.

In a first aspect, there is provided an extended release pharmaceuticaldosage form comprising an active pharmaceutical ingredient (API) and arelease modifying excipient, the release modifying excipient comprising:35% to 95% (wt/wt) of a high amylose starch, 1% to 40% (wt/wt) of across-linked hydroxypropylated amylopectin, and 1% to 30% (wt/wt) of apre-gelatinized common starch, wherein the release modifying excipientis substantially free of crosslinks between amylose and amylopectinsubunits and substantially free of crosslinks between amylose andamylose subunits.

In another aspect, there is provided an extended release pharmaceuticaldosage form comprising: tramadol or a pharmaceutically acceptable saltthereof and a release modifying excipient, the release modifyingexcipient comprising: 70-80% (wt/wt) of a high amylose starch, 10-20%(wt/wt) of a cross-linked hydroxypropylated amylopectin, and 5-15%(wt/wt) of a pre-gelatinized common starch, wherein the releasemodifying excipient is substantially free of crosslinks between amyloseand amylopectin subunits and substantially free of crosslinks betweenamylose and amylose subunits.

In another aspect, there is provided an extended release pharmaceuticaldosage form comprising: trazodone or a pharmaceutically acceptable saltthereof and a release modifying excipient, the release modifyingexcipient comprising: 70-80% (wt/wt) of a high amylose starch, 10-20%(wt/wt) of a cross-linked hydroxypropylated amylopectin, and 5-15%(wt/wt) of a pre-gelatinized common starch, wherein the releasemodifying excipient is substantially free of crosslinks between amyloseand amylopectin subunits and substantially free of crosslinks betweenamylose and amylose subunits.

In another aspect, there is provided a bilayer extended releasepharmaceutical dosage form comprising: an immediate release portioncomprising acetaminophen, and a release controlling portion comprisingacetaminophen and a release modifying excipient, the release modifyingexcipient comprising: 70-80% (wt/wt) of a high amylose starch, 10-20%(wt/wt) of a cross-linked hydroxypropylated amylopectin, and 5-15%(wt/wt) of a pre-gelatinized common starch, wherein the releasemodifying excipient is substantially free of crosslinks between amyloseand amylopectin subunits and substantially free of crosslinks betweenamylose and amylose subunits.

In another aspect, there is provided a use of the extended releasepharmaceutical dosage defined herein for delivery the API to a subject.

In another aspect, there is provided a method of delivering an API to asubject comprising administering to the subject the pharmaceuticaldosage form as defined herein.

In another aspect, there is provided a method of optimizing a releasecontrolling excipient for an active pharmaceutical ingredient (API), themethod comprising: selecting a target release property for a dosage fromcomprising the API, selecting an amount of a high amylose starch,selecting an amount of a cross-linked hydroxypropylated amylopectin, andselecting an amount of a pre-gelatinized common starch, blending thehigh amylose starch, the cross-linked hydroxypropylated amylopectin, andthe pre-gelatinized common starch using the selected amounts to form arelease controlling excipient, wherein the release controlling excipientis substantially free of crosslinks between amylose and amylopectinsubunits and substantially free of crosslinks between amylose andamylose subunits, forming a dosage form comprising the API and therelease controlling excipient, and testing the dosage form to determineconformity with the target release property.

Other aspects and features of the present disclosure will becomeapparent to those ordinarily skilled in the art upon review of thefollowing description of specific embodiments in conjunction with theaccompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described, by way ofexample only, with reference to the attached Figures.

FIG. 1 depicts the proportion of API release in vitro over time shown asa measure of dissolution performance of intact acetaminophen dosageforms.

FIG. 2 depicts mean plasma acetaminophen concentrations over time asgenerated by dosage forms of composition according to Table 2. Thebiphasic nature of the in vitro dissolution profile is reflected in thein vivo pharmacokinetics generated by the dosage forms.

FIG. 3 depicts the proportion of acetaminophen released over time fromacetaminophen dosage forms manufactured with ER layers comprising eachof the starch Test Blends shown in Table 1. Test Blends generatingfaster, identical and slower release of acetaminophen over time comparedto Contramid were identified.

FIG. 4 depicts the proportion of API released as a measure ofdissolution performance of the bilayer acetaminophen formulation with ERlayer comprising Contramid® or the HAS/CMAP/PGS blend.

FIG. 5 depicts the proportion of API released as a measure ofdissolution performance of the acetaminophen dosage forms shown in FIG.4 in both the intact and bisected form.

FIG. 6 depicts the proportion of API released as a measure ofcomparative in vitro dissolution performance of trazodone ER dosageforms manufactured using Contramid® or the 75:15:10 starch blend.

FIG. 7 depicts dissolution profiles for tramadol formulations across apH range, and in alcohol. Large circles (on the black line) indicate pH6.8, black squares (on the black small dotted line) indicate pH 4.5,black triangles (on the black large dotted line) indicate pH 1.2, andblack asterisks (on the bottom-most line) indicate 40% ethanol at pH6.8.

FIG. 8 shows dissolution profiles for subdivided halves of a tramadolformulation comprising the novel release modifying excipient (bottomcurve) versus a comparable tramadol formulation (Tridural®) comprisingContramid.

DETAILED DESCRIPTION

Generally, the present disclosure teaches extended release dosage formscomprising a release modifying excipient comprising blended high amylosestarch, cross-linked hydroxypropylated amylopectin, and apre-gelatinized common starch; wherein the released modifying excipientis substantially free of crosslinks between amylose and amylopectin andsubstantially free of crosslinks between amylose and amylose.Corresponding medical uses and methods are also provided; along withmethods formulating a blend optimized for release of a particular activepharmaceutical agent.

It has been found that the release modifying properties of conventionalCLHAS (e.g., Contramid®) can be reproduced in ER dosage forms by mixing;i) cross-linked chemically modified amylopectin; ii) a high amylose,non-chemically modified starch and; iii) a pre-gelatinized common starchaccording to some embodiments. This finding is surprising, as producinga release modifying excipient in this way means that no cross-linking ofamylose to amylopectin occurs and no cross-linked amylose-amylose ispresent. These cross-linked components were previously considered vitalfor Contramid® function. The approach lends itself to flexibleformulation processes in which the proportions of the blend componentsare adjusted to modify properties.

Dosage Forms

In one aspect, there is provided an extended release pharmaceuticaldosage form comprising an active pharmaceutical ingredient (API) and arelease modifying excipient, the release modifying excipient comprising35 to 95% (wt/wt) of a high amylose starch, 1 to 40% (wt/wt) of across-linked hydroxypropylated amylopectin, and 1 to 30% (wt/wt) of apre-gelatinized common starch, wherein the release modifying excipientis substantially free of crosslinks between amylose and amylopectinsubunits and substantially free of crosslinks between amylose andamylose subunits.

Where “wt/wt” amounts are specified in this context, this will beunderstood as being based on the total weight of the dosage form unlessotherwise indicated.

By “active pharmaceutical ingredient (API)” is meant an agent that has atherapeutic or health-promoting effect when administered to a human oran animal, for example, an agent capable of treating or preventing adisease or condition. Examples of therapeutic agents include, but arenot limited to, drugs, prodrugs, vitamins and supplements.

By “release modifying excipient” is meant an agent that, in a dosageform, affects the release rate of an API incorporated in the dosageform, such dosage form then releasing the API at a rate that is at leasttwo-fold slower than would be achieved compared to an immediate release(IR) dosage form. CLHAS, hydroxypropyl cellulose (HPC), polyethyleneoxide (PEO) sodium lauryl sulphate (SLS), copovidone, and hypromelloseare release modifying excipients.

By “amylose” will be understood the component starch that is a helicalpolymer made from α-D-glucose units, bonded to each other through α(1→4)glycosidic bonds. Amylose is a linear carbohydrate, and is generally oflower molecular weight than amylopectin.

By “high amylose starch” (HAS) is meant a starch comprising of at least50% amylose (wt/wt). Examples of commercially available HAS includeHylon VII™ Amylogel™ 03003, Hylon V, High Maize, Amylose Maize N400 andEurylon G.

The high amylose starch may be non-chemically modified, i.e. free ofchemical modification. For example, it may be non-crosslinked.

In one embodiment, the HAS comprises Hylon VII™.

By “amylopectin” will be understood the component starch is apolysaccharide and highly branched polymer of glucose. Glucose units arelinked in a linear way with α(1→4) glycosidic bonds. Branching takesplace with α(1→6) bonds occurring typically every 24 to 30 glucoseunits.

By “cross-linked hydroxypropylated amylopectin” (a type of cross-linkedmodified amylopectin, or “CMAP”) is meant amylopectin that has beenchemically modified to form covalent bonds between (and/or within)amylopectin molecules, and in which native amylopectin is substitutedwith hydroxypropyl groups. For example, hydroxypropylation may increasethe gel stability, water solubility, digestibility, and storagestability of the native molecules. Examples include Utra-Tex4™, Pure-GelB990™, Polar Tex-instant 12640™, and Polar-Tex-instant 12643™.

In one embodiment, the cross-linked hydroxypropylated amylopectincomprises Ultra-Tex4™.

By “pre-gelatinized common starch” (PGS) is meant a starch comprisingnot more than 50% amylopectin (wt/wt) that is subject to gelatinization,a process of breaking down the intermolecular bonds of starch moleculesin the presence of water and heat, allowing the hydrogen bonding sites(the hydroxyl hydrogen and oxygen) to engage more water. Examplesinclude Starch 1500™, SuperStarch 200™, and National 78-1551™.

In one embodiment, the PGS comprises Starch 1500™.

In one embodiment, the release modifying excipient comprises 35 to 95%(wt/wt) high amylose starch. In one embodiment, the release modifyingexcipient comprises 40 to 90% (wt/wt) high amylose starch. In oneembodiment, the release modifying excipient comprises 45 to 85% (wt/wt)high amylose starch. In one embodiment, the release modifying excipientcomprises 50 to 80% high amylose starch. In one embodiment, the releasemodifying excipient comprises 70 to 80% (wt/wt) high amylose starch.

In one embodiment, the release modifying excipient comprises 1 to 40%(wt/wt) of the cross-linked hydroxypropylated amylopectin. In oneembodiment, the release modifying excipient comprises 5 to 30% (wt/wt)of the cross-linked hydroxypropylated amylopectin. In one embodiment,the release modifying excipient comprises 10 to 20% (wt/wt) of thecross-linked hydroxypropylated amylopectin.

In one embodiment, the release modifying excipient comprises 1 to 30%(wt/wt) of the pre-gelatinized common starch. In one embodiment, therelease modifying excipient comprises 2 to 20% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingexcipient comprises 5 to 15% (wt/wt) of the pre-gelatinized commonstarch.

In one embodiment, the release modifying excipient comprises 55% to 65%(wt/wt) of the high amylose starch, 30% to 40% (wt/wt) of thecross-linked hydroxypropylated amylopectin, and 1% to 10% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingagent comprises about 60% (wt/wt) of the high amylose starch, about 35%(wt/wt) of the cross-linked hydroxypropylated amylopectin, and about 5%(wt/wt) of the pre-gelatinized common starch. This is in accordance withBlend 1 (see Example 1).

By “about”, as used herein, is meant within 10% above of or below thestated reference value.

In one embodiment, the release modifying excipient comprises 65% to 75%wt/wt) of the high amylose starch, 1% to 10% (wt/wt) of the cross-linkedhydroxypropylated amylopectin, and 20% to 30% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingagent comprises about 70% (wt/wt) of the high amylose starch, about 5%(wt/wt) of the cross-linked hydroxypropylated amylopectin, and about 25%(wt/wt) of the pre-gelatinized common starch. This is in accordance withBlend 2 (see Example 1).

In one embodiment, the release modifying excipient comprises 70% to 80%(wt/wt) of the high amylose starch, 10% to 20% (wt/wt) of thecross-linked hydroxypropylated amylopectin, and 5% to 15% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingagent comprises about 75% (wt/wt) of the high amylose starch, about 15%(wt/wt) of the cross-linked hydroxypropylated amylopectin, and about 10%(wt/wt) of the pre-gelatinized common starch. This is in accordance withBlend 3 (see Example 1).

In one embodiment, the release modifying excipient comprises 85% to 95%(wt/wt) of the high amylose starch, 1% to 10% (wt/wt) of thecross-linked hydroxypropylated amylopectin, and 1% to 10% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingagent comprises about 90% (wt/wt) of the high amylose starch, about 5%(wt/wt) of the cross-linked hydroxypropylated amylopectin, and about 5%(wt/wt) of the pre-gelatinized common starch. This is in accordance withBlend 4 (see Example 1).

In one embodiment, the API is an analgesic, anesthetic, serotoninreuptake inhibitor, 5-HT_(2A) receptor antagonist, opiate receptoragonist, norepinephrine reuptake inhibitor, cardiovascular drug,metformin, or sulphonylurea.

By “analgesic” is meant any member of the group of drugs used to achievereduction or relief of pain in mammals. Non-limiting examples includeacetaminophen/paracetamol, nonsteroidal anti-inflammatory drugs(NSAIDs), COX-2 inhibitors, opioids, etc.

By “NSAID” is meant a non-narcotic drug that provides analgesic(pain-killing) and antipyretic (fever-reducing) effects, and, in higherdoses, anti-inflammatory effects. Non-limiting examples include aspirin,ibuprofen, naproxen, flurbiprofen, and melxoicam.

By “COX-2 inhibitor” is meant a drug that selectively inhibits thecyclooxygenase-2 enzyme in mammals. In one embodiment, the COX-2inhibitor comprises celecoxib

By “anesthetic” is meant one of the drugs used to prevent pain inmammals, e.g. during surgery. Non-limiting examples of non-opioidanesthetics include Barbiturates (e.g. Amobarbital, Methohexital,Thiamylal, Thiopental), Benzodiazepines (e.g., Diazepam, Lorazepam,Midazolam), Etomidate, Ketamine, and Propofol.

Non-limiting examples of opioid anesthetics include Alfentanil,Fentanyl, Remifentanil, Sufentanil, Buprenorphine, Butorphanol, diacetylmorphine, Hydromorphone, Levorphanol, Meperidine, Methadone, Morphine,Nalbuphine, Oxycodone, Oxymorphone, Pentazocine, Tramadol, andTapentadol.

By “serotonin reuptake inhibitor” is meant a drug that blocks the actionof the serotonin transporter (SERT) in mammals and provides, forexample, antidepressant, and antianxiety effects. Some examples includetrazodone, tramadol, citalopram and vortioxetine.

By “5-HT_(2A) receptor antagonist” is meant a drug that reduces theeffects of the 5-HT2A receptor of mammals.

By “opiate receptor agonist” is meant a drug that enhances the effectsof an opiate receptor of mammals.

By “norepinephrine reuptake inhibitor” is meant a drug that blocks theaction of the norepinephrine transporter (NET) of mammals and provides,for example, psychostimulant effects, appetite suppressant effects,antidepressant, and antianxiety effects.

By “cardiovascular drug” is meant a drug that has an effect on thecardiovascular system of mammals.

In one embodiment, the API comprises acetaminophen.

In one embodiment, the API comprises celecoxib

In one embodiment, the API comprises flurbiprofen.

In one embodiment, the API comprises trazodone or a pharmaceuticallyacceptable salt thereof.

In one embodiment, the API comprises meloxicam or a pharmaceuticallyacceptable salt thereof.

In one embodiment, the API comprises metformin or a pharmaceuticallyacceptable salt thereof.

In one embodiment, the API comprises tramadol or a pharmaceuticallyacceptable salt thereof.

In one embodiment, the extended release pharmaceutical dosage form hassubstantially the same release profile and/or pharmacokinetics as adosage form comprising an equivalent amount of cross-linked high amylosestarch.

By “substantially the same” is meant less than a statisticallysignificant difference between the release profile of the extendedrelease pharmaceutical dosage form and the release profile of thereference pharmaceutical dosage form.

By “release profile” is meant the dissolution profile of the tablet andrate of release of the API.

In some embodiment, the extended release pharmaceutical dosage formexceeds the release profile and/or pharmacokinetics of a dosage formcomprising an equivalent amount of cross-linked high amylose starch.

The term “exceeds” will be understood in context, such that when a lowrelease rate is desirable, “exceeds” indicates an even lower releaserate.

It has surprisingly been found that release modifying excipients,according to some embodiments, can recapitulate or exceed the releasemodifying properties of cross-linked high amylose starch. It isunexpected that a blend of ingredients, according to some embodiments,including pre-modified (e.g., cross-linked and hydroxypropylated)amylopectin, can recapitulate or exceed the release modifying propertiesof cross-linked high amylose starch, in which the components of theeffective blend are modified together.

Release profiles can be compared using established statistical methods.For example, a difference factor (f₁) and a similarity factor (f₂) maybe calculated for two curves using established methods.³ In oneembodiment, a release profile that is “substantially the same” may havean f₁ value from 0 to 15 and an f₂ value from 50 to 100. In oneembodiment, the f₁ value may be up to 15. The f₁ value may be up to 10.The f₁ value may be up to 5. In one embodiment, a release profile thatis “substantially the same” may have an f₂ value of 50 or greater. Thef₂ value may be above 60. The f₂ value may 70 or greater. The f₂ valuemay be 80 or greater. The f₂ value may be 90 or greater.

In another embodiment, the extended release pharmaceutical dosage formhas substantially the same release profile in dissolution media havingpH 1 to 7.

In another embodiment, the extended release pharmaceutical dosage formhas a lower release rate in an ethanol-containing dissolution mediacompared to non-ethanol-containing dissolution media. In someembodiments, the release rate in the ethanol-containing dissolutionmedia may be substantially the same as that of a dosage form comprisingan equivalent amount of cross-linked high amylose starch. In someembodiments, the release rate in the ethanol-containing dissolutionmedia may be lower than that of a dosage form comprising an equivalentamount of cross-linked high amylose starch.

In another embodiment, the extended release pharmaceutical dosage has adrug loading level of at least 60%.

By “drug loading level” (DLL) as referred to herein is meant the weightratio of the API to the total weight of the dosage form.

The DLL may be at least 5%. The DLL may be at least 10%. The DLL may beat least 15%. The DLL may be at least 20%.The DLL may be at least 25%.The DLL may be at least 30%. The DLL may be at least 35%. The DLL may beat least 40%. The DLL may be at least 45%. The DLL may be at least 50%.The DLL may be at least 55%. The DLL may be at least 60%. The DLL may beat least 65%. The DLL may be at least 70%. The DLL may be at least 75%.The DLL may be at least 80%. The DLL may be at least 85%. The DLL may beat least 90%.

In one embodiment, the extended release pharmaceutical dosage form isbreakable. In one embodiment, the extended release pharmaceutical dosageform is scored.

In one embodiment, the extended release pharmaceutical dosage form isbisectable. In one embodiment, the extended release pharmaceuticaldosage form is scored.

In one embodiment, the extended release pharmaceutical dosage form istri-sectable. In one embodiment, the extended release pharmaceuticaldosage form is scored.

In one embodiment, the extended release pharmaceutical dosage form isquarter-sectable. In one embodiment, the extended release pharmaceuticaldosage form is scored.

By “scored” is meant notched, indented, or partially cut to facilitatesubdivision. Any suitable modification to the dosage form thatfacilitates subdivision is intended.

In one embodiment, when the extended release pharmaceutical dosage formis subdivided, the subdivided portions have substantially the samerelease profile and/or pharmacokinetics as the intact dosage form. Inone embodiment, the substantially the same release profile of thesubdivided portions comprises an f₂ value of at least 50% with respectto the intact dosage form.

In one embodiment, upon subdivision, subdivided portions of the dosageform release less than 50% of the API at four hours, as measured in aUSP Type III Apparatus in 900 mL of pH 6.8 phosphate buffer at 100 rpmat a temperature of 37° C.

In one embodiment, the extended release pharmaceutical dosage formcomprises an IR portion comprising a first portion of the API, and arelease modifying portion comprising a second portion of the API and therelease modifying excipient.

By “immediate release” is meant that release of the API is not delayedupon ingestion, such that the biological effect is also note delayedbeyond normal onset of action times.

In another aspect, the extended release pharmaceutical dosage form, theratio of the release modifying excipient to the API in the releasemodifying portion is less than 1:7. The ratio may be between 1:1.5 to1:7. In some embodiments it will be understood that these ratios arebased on weights.

In one embodiment, the extended release pharmaceutical dosage providesan at least two-fold reduction in dosage frequency relative to animmediate release dosage form comprising the same amount of API.

In another aspect, the extended release pharmaceutical dosage formcontains cross-linked hydroxypropylated amylopectin with no more than 7%(wt/wt) hydroxypropylated propyl groups.

In another aspect, the extended release pharmaceutical dosage formcontains cross-linked hydroxypropylated amylopectin with no more than0.04% (wt/wt) residual phosphate.

In another aspect, the extended release pharmaceutical dosage formcontains cross-linked hydroxypropylated amylopectin with no more than 1part per million of propylene chlorhydrin.

In another aspect, the extended release pharmaceutical dosage formcomprises tramadol and a release modifying excipient, the releasemodifying excipient comprising 70-80% of the high amylose starch, 10-20%of the cross-linked hydroxypropylated amylopectin, and 5-15% of thepre-gelatinized common starch and the release modifying excipient issubstantially free of crosslinks between amylose and amylopectinsubunits and substantially free of crosslinks between amylose andamylose subunits. In one embodiment, the extended release pharmaceuticaldosage form comprises 100 mg, 150 mg, 200 mg, or 300 mg of tramadol. Inone embodiment, the extended release pharmaceutical dosage form isbisectable. In one embodiment, the extended release pharmaceuticaldosage form is scored. In one embodiment, upon subdivision, the dosageform maintains substantially the same release profile for the tramadolas the intact dosage form. In one embodiment, the dosage form comprises13 to 56% (wt/wt) tramadol and 5 to 20% (wt/wt) combined weight of thehigh amylose starch, the cross-linked hydroxypropylated amylopectin, andthe pre-gelatinized common starch. In one embodiment, the dosage formcomprises 22 to 33% (wt/wt) tramadol and 5 to 15% (wt/wt) combinedweight of the high amylose starch, the cross-linked hydroxypropylatedamylopectin, and the pre-gelatinized common starch. In one embodiment,upon subdivision, the two subdivided portions release less than 50% ofthe tramadol at four hours, as measured in a USP Type III Apparatus in900 mL of pH 6.8 phosphate buffer at 100 rpm at a temperature of 37° C.

In another aspect, the extended release pharmaceutical dosage formcomprises trazodone and a release modifying excipient, the releasemodifying excipient comprising 70-80% of the high amylose starch, 10-20%of the cross-linked hydroxypropylated amylopectin, and 5-15% of thepre-gelatinized common starch and the release modifying excipient issubstantially free of crosslinks between amylose and amylopectinsubunits and substantially free of crosslinks between amylose andamylose subunits. In one embodiment, the extended release pharmaceuticaldosage form comprises 150 mg or 300 mg of trazodone. In one embodiment,the extended release pharmaceutical dosage form is bisectable. In oneembodiment, the extended release pharmaceutical dosage form is scored.In one embodiment, upon subdivision, the dosage form maintainssubstantially the same release profile for the trazodone as the intactdosage form. In one embodiment, the dosage form comprises 25 to 75%(wt/wt) trazodone and 15 to 60% (wt/wt) combined weight of the highamylose starch, the cross-linked hydroxypropylated amylopectin, and thepre-gelatinized common starch. In one embodiment, the dosage formcomprises 45 to 55% (wt/wt) trazodone and 27 to 38% (wt/wt) combinedweight of the high amylose starch, the cross-linked hydroxypropylatedamylopectin, and the pre-gelatinized common starch. In one embodiment,upon subdivision, the two subdivided portions release less than 50% ofthe trazodone at four hours, as measured in a USP Type III Apparatus in900 mL of pH 6.8 phosphate buffer at 100 rpm at a temperature of 37° C.

In another aspect, the pharmaceutical dosage form comprises a bilayerwith an immediate release portion comprising acetaminophen, and arelease modifying portion comprising acetaminophen and a releasemodifying excipient comprising 70-80% of the high amylose starch, 10-20%of the cross-linked hydroxypropylated amylopectin, and 5-15% of thepre-gelatinized common starch, and the release modifying excipient issubstantially free of crosslinks between amylose and amylopectinsubunits and substantially free of crosslinks between amylose andamylose subunits. In one embodiment, the extended release pharmaceuticaldosage form comprises 500 mg, 750 mg, or 1000 mg of acetaminophen. Inone embodiment, the extended release pharmaceutical dosage form isbisectable. In one embodiment, the extended release pharmaceuticaldosage form is scored. In one embodiment, upon subdivision, the dosageform maintains substantially the same release profile for theacetaminophen, as the intact dosage form. In one embodiment, the dosageform comprises 49 to 69% (wt/wt) acetaminophen and 3.5 to 13% (wt/wt)combined weight of the high amylose starch, the cross-linkedhydroxypropylated amylopectin, and the pre-gelatinized common starch. Inone embodiment, upon subdivision, the two subdivided portions releaseless than 50% of the acetaminophen at four hours, as measured in a USPType III Apparatus in 900 mL of pH 6.8 phosphate buffer at 100 rpm at atemperature of 37° C.

In another aspect, the extended release pharmaceutical dosage formreleases the API over at least 12 hours as measured using a USP Type IIIapparatus at a rate of 20 dips per minute, in a dissolution medium of 50mM potassium phosphate buffer pH 6.8 (250 mL) at a temperature of 37° C.

The dosage form may release the API over at least 6, 8, 10, 12, or 14hours.

In one embodiment, the extended release dosage form herein describedfurther comprises an additional release modifying excipient. In oneembodiment, the additional release modifying excipient may comprisehydroxypropyl methylcellulose (“hypromellose” or HPMC), hydroxypropylmethylcellulose blend, polyvinyl acetate/polyvinylpyrrolidone blend,and/or xanthan gum.

In one embodiment, the additional release modifying excipient compriseshydroxypropyl methylcellulose. The hydroxypropyl methylcellulose may bepresent in an amount of 1 to 50% w/w. In another embodiment,hydroxypropyl methylcellulose may be present in an amount of 5 to 35%w/w. In another embodiment, hydroxypropyl methylcellulose may be presentin an amount of 10 to 20% w/w. In another embodiment, hydroxypropylmethylcellulose may be present in an amount of about 16% w/w.

In one embodiment, the hydroxypropyl methylcellulose may comprises,e.g., K100M. The K100M may be present in an amount of 1 to 50% w/w. Inanother embodiment, the K100M may be present in an amount of 5 to 35%.In another embodiment, the K100M may be present in an amount of 10 to20% w/w. In another embodiment, the K100M may be present in an amount ofabout 16% w/w as in the Example 2 formulation.

In another embodiment, the hydroxypropyl methylcellulose may comprise ablend of K100 and K100M. The blend may be present in an amount of 1 to90%. In another embodiment, the blend may be present in an amount of 2to 30%. In another embodiment, the blend may be present in an amount of3 to 15% w/w. In another embodiment, the blend may be present in anamount of about 5.4% w/w, as in the Example 1 formulation.

In another embodiment the additional release modifying excipientcomprises a polyvinyl acetate/polyvinylpyrrolidone blend. The polyvinylacetate/polyvinylpyrrolidone may be present in an amount of 10 to 90%.In another embodiment, the polyvinyl acetate/polyvinylpyrrolidone blendmay be present in an amount of 30 to 70%. In another embodiment, thepolyvinyl acetate/polyvinylpyrrolidone blend may be present in an amountof 45 to 55% w/w. In another embodiment, the polyvinylacetate/polyvinylpyrrolidone blend may be present in an amount of about40% w/w.

In another embodiment, the polyvinyl acetate/polyvinylpyrrolidone blendmay comprise Kollidon SR. The Kollidon SR may be present in an amount of10 to 90%. In another embodiment, the Kollidon SR may be present in anamount of 30 to 70%. In another embodiment, the Kollidon SR may bepresent in an amount of 45 to 55% w/w. In another embodiment, theKollidon SR may be present in an amount of about 40% w/w, as in theformulation of Example 3.

In another embodiment the additional release modifying excipientcomprises xanthan gum. The xanthan gum may be present in an amount of 10to 90% w/w. In another embodiment, xanthan gum may be present in anamount of 30 to 70% w/w. In another embodiment, xanthan gum may bepresent in an amount of 15 to 25% w/w. In another embodiment, xanthangum may be present in an amount of about 20% w/w.

In another embodiment, the xanthan gum may comprise Xantural 180. TheXantural 180 may be present in an amount of 10 to 90% w/w. In anotherembodiment, Xantural 180 may be present in an amount of 30 to 70% w/w.In another embodiment, Xantural 180 may be present in an amount of 15 to25% w/w. In another embodiment, Xantural 180 may be present in an amountof about 20% w/w, as in the Example 3 formulation.

In one embodiment, the extended release dosage form further comprises adisintegrant. The disintegrant may be, for example, croscarmellosesodium, crospovidone, or sodium starch glycolate. For example,croscarmellose sodium (e.g. Vivasol) GF may be present in an amount of0.05 to 5% w/w. In another embodiment, croscarmellose sodium may bepresent in an amount of 0.1 to 3% w/w. In another embodiment,croscarmellose sodium may be present in an amount of 0.25 to 1% w/w. Inanother embodiment, croscarmellose sodium may be present in an amount ofabout 0.45% w/w as in the Example 1 formulation.

In one embodiment, the extended release dosage form further comprises aglidant. In one embodiment, the glidant may be colloidal silicon dioxideor talc. For example, colloidal silicon dioxide (e.g. Cab-o-sil M-5P)may be present in an amount of 0.05 to 5% w/w. In another embodiment,colloidal silicon dioxide may be present in an amount of 0.1 to 3% w/w.In another embodiment, colloidal silicon dioxide may be present in anamount of 0.25 to 1% w/w. In another embodiment, colloidal silicondioxide may be present in an amount of 0.39% w/w, 0.5% or 0.18%,respectively, as in the Examples 1, 2 and 3 formulations.

In one embodiment, the extended release dosage form further comprises alubricant. In one embodiment, the lubricant may be hydrogenatedvegetable oil, magnesium stearate or sodium stearyl fumarate. Forexample, magnesium stearate (e.g. Ligamed MF-2V) may be present in anamount of 0.05 to 5% w/w. In another embodiment, magnesium stearate maybe present in an amount of 0.1 to 3% w/w. In another embodiment,magnesium stearate may be present in an amount of 0.25 to 1% w/w. Inanother embodiment, magnesium stearate may be present in an amount ofabout 0.5% as in the Example 3 formulation. In another embodiment,sodium stearyl fumarate (e.g. Pruv) may be present in an amount of 0.25to 5%. In another embodiment, sodium stearyl fumarate I may be presentin an amount of 0.5 to 3%. In another embodiment, sodium stearylfumarate may be present in an amount of 1 to 2% w/w. In anotherembodiment, sodium stearyl fumarate may be present in an amount of 1.2%w/w and 1.5% w/w from examples 1 and 2 formulations. In anotherembodiment, hydrogenated vegetable oil e.g. Lubritab may be present inan amount of 0.05 to 10%. In another embodiment, hydrogenated vegetableoil may be present in an amount of 0.25 to 5%. In another embodiment,hydrogenated vegetable oil may be present in an amount of 0.5 to 1.5%w/w. In another embodiment, hydrogenated vegetable oil may be present inan amount of about 0.9% w/w as in the Example 3 formulation.

In one embodiment, the extended release dosage form further comprises abinder. In one embodiment, the binder may be carbomers, carboxymethylcellulose, copovidone, hydroxypropyl cellulose, guar gum, polyethyleneoxide or povidone. For example, copovidone may be present in an amountof 0.1 to 10% w/w. In another embodiment, copovidone may be present inan amount of 0.5 to 5% w/w. In another embodiment, copovidone may bepresent in an amount of 2 to 3% w/w. In another embodiment, copovidonemay be present in an amount of about 2.3% w/w as in the Example 1formulation.

Uses and Methods

In another aspect, there is provided a use of the extended releasepharmaceutical dosage form describe herein for delivery of an API to asubject.

In another aspect, there provides a use of the extended releasepharmaceutical dosage form describe herein for preparation of amedicament for delivery of an API to a subject.

In another aspect, there provides an extended release pharmaceuticaldosage form as defined herein for use in delivery of an API to asubject.

In one aspect, there is provided a method of delivering an API to asubject comprising administering to the subject the pharmaceuticaldosage form as described herein.

In one embodiment, the extended release pharmaceutical dosage form hassubstantially the same release profile and/or pharmacokinetics as adosage form comprising an equivalent amount of cross-linked high amylosestarch (e.g. Contramid).

The subject may be human.

The subject may be non-human. The subject may be a non-human mammal.

By “pharmaceutically effective level” is meant the minimum blood plasmaconcentration of API required to illicit the intended biologicalreaction or effect in a mammalian system.

The use, dosage form for use, or method may be for delivery thepharmaceutically effective level of the API for at least 8 hours, 10hours, 12 hours or 24 hours.

In one embodiment, the use, dosage form for use, or method is fordelivery of a pharmaceutically effective level of the API to the subjectover at least 8 hours.

In one embodiment, the use, dosage form for use, or method is fordelivery of a pharmaceutically effective level of the API to the subjectover at least 10 hours.

In one embodiment, the use, dosage form for use, or method is fordelivery of a pharmaceutically effective level of the API to the subjectover at least 12 hours.

In another aspect, there is provided a use of a release modifyingexcipient comprising 35 to 95% (wt/wt) of a high amylose starch, 1 to40% (wt/wt) of a cross-linked hydroxypropylated amylopectin, and 1 to30% (wt/wt) of a pre-gelatinized common starch, wherein the releasemodifying excipient is substantially free of crosslinks between amyloseand amylopectin subunits and substantially free of crosslinks betweenamylose and amylose subunits, for reproducing the release modifyingproperty for an API of a CLHAS. Accordingly, the use would providesubstantially the same release modifying property. In one embodiment,the use is for reproducing the release modifying property of anequivalent amount of a CLHAS. In one embodiment, the use is forexceeding the release modifying property of an equivalent amount of aCLHAS.

In another aspect, there is provided a release modifying excipientcomprising 35 to 95% (wt/wt) of a high amylose starch, 1 to 40% (wt/wt)of a cross-linked hydroxypropylated amylopectin, and 1 to 30% (wt/wt) ofa pre-gelatinized common starch, wherein the release modifying excipientis substantially free of crosslinks between amylose and amylopectinsubunits and substantially free of crosslinks between amylose andamylose subunits, for use in reproducing the release modifying propertyfor an API of a CLHAS. Accordingly, the release modifying excipientwould provide substantially the same release modifying property. In oneembodiment, the release modifying excipient is for use reproducing therelease modifying property of an equivalent amount of a CLHAS. In oneembodiment, the release modifying excipient is for use is for exceedingthe release modifying property of an equivalent amount of a CLHAS.

Formulation Methods

In another aspect, there is provided a method for optimizing a releasemodifying excipient for an active pharmaceutical ingredient (API), themethod comprising: selecting a target release property for a dosage fromcomprising the API, selecting an amount of a high amylose starch,selecting an amount of a cross-linked hydroxypropylated amylopectin, andselecting an amount of a pre-gelatinized common starch, blending thehigh amylose starch, the cross-linked hydroxypropylated amylopectin, andthe pre-gelatinized common starch using the selected amounts to form arelease modifying excipient, wherein the release modifying excipient issubstantially free of crosslinks between amylose and amylopectinsubunits and substantially free of crosslinks between amylose andamylose subunits, forming a dosage form comprising the API and therelease modifying excipient, and testing the dosage form to determineconformity with the target release property.

In some embodiments, the flexibility afforded by the ability to blendpre-existing ingredients means that the release modifying properties ofthe release modifying excipient can be more readily adjusted or tailoredto an API of interest, and/or to recapitulate or exceed the releasemodifying properties of a dosage form comprising another releasemodifying excipient, such as a conventional CLHAS. In some embodiments,an aim is to recapitulate the release modifying properties of a dosageform comprising another release modifying excipient, such as aconventional CLHAS.

By “target release property” is meant, in some embodiments, the desiredAPI dissolution rate from the dosage form.

In one embodiment, the target release property is from a referencedosage form. In one embodiment, the target release property is from areference dosage form comprising the API and a conventional cross-linkedhigh amylose starch release modifying excipient.

In one embodiment, the amount of release modifying excipient in thedosage form does not exceed the amount of cross-linked high amylosestarch release modifying excipient in the reference dosage form.

In one aspect, there is provided a method of mixing the amylose starch,the cross-linked hydroxypropylated amylopectin, and the pre-gelatinizedcommon starch described herein to form the release modifying excipientdescribed herein.

In one aspect, there is provided a method of mixing the releasemodifying excipient defined herein with the API to form the dosage formdescribed herein.

In one embodiment, the release modifying excipient may comprise any oneor more of the properties herein described.

For example, the release modifying excipient may comprises 35 to 95%(wt/wt) of a high amylose starch, 1 to 40% (wt/wt) of a cross-linkedhydroxypropylated amylopectin, and 1 to 30% (wt/wt) of a pre-gelatinizedcommon starch.

In one embodiment, the release modifying excipient comprises 35 to 95%(wt/wt) high amylose starch. In one embodiment, the release modifyingexcipient comprises 40 to 90% (wt/wt) high amylose starch. In oneembodiment, the release modifying excipient comprises 45 to 85% (wt/wt)high amylose starch. In one embodiment, the release modifying excipientcomprises 50 to 80% high amylose starch. In one embodiment, the releasemodifying excipient comprises 70 to 80% (wt/wt) high amylose starch.

In one embodiment, the release modifying excipient comprises 1 to 40%(wt/wt) of the cross-linked hydroxypropylated amylopectin. In oneembodiment, the release modifying excipient comprises 5 to 30% (wt/wt)of the cross-linked hydroxypropylated amylopectin. In one embodiment,the release modifying excipient comprises 10 to 20% (wt/wt) of thecross-linked hydroxypropylated amylopectin.

In one embodiment, the release modifying excipient comprises 1 to 30%(wt/wt) of the pre-gelatinized common starch. In one embodiment, therelease modifying excipient comprises 2 to 20% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingexcipient comprises 5 to 15% (wt/wt) of the pre-gelatinized commonstarch.

In one embodiment, the release modifying excipient comprises 55% to 65%(wt/wt) of the high amylose starch, 30% to 40% (wt/wt) of thecross-linked hydroxypropylated amylopectin, and 1% to 10% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingagent comprises about 60% (wt/wt) of the high amylose starch, about 35%(wt/wt) of the cross-linked hydroxypropylated amylopectin, and about 5%(wt/wt) of the pre-gelatinized common starch. This is in accordance withBlend 1 (see Example 1).

In one embodiment, the release modifying excipient comprises 65% to 75%wt/wt) of the high amylose starch, 1% to 10% (wt/wt) of the cross-linkedhydroxypropylated amylopectin, and 20% to 30% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingagent comprises about 70% (wt/wt) of the high amylose starch, about 5%(wt/wt) of the cross-linked hydroxypropylated amylopectin, and about 25%(wt/wt) of the pre-gelatinized common starch. This is in accordance withBlend 2 (see Example 1).

In one embodiment, the release modifying excipient comprises 70% to 80%(wt/wt) of the high amylose starch, 10% to 20% (wt/wt) of thecross-linked hydroxypropylated amylopectin, and 5% to 15% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingagent comprises about 75% (wt/wt) of the high amylose starch, about 15%(wt/wt) of the cross-linked hydroxypropylated amylopectin, and about 10%(wt/wt) of the pre-gelatinized common starch. This is in accordance withBlend 3 (see Example 1).

In one embodiment, the release modifying excipient comprises 85% to 95%(wt/wt)of the high amylose starch, 1% to 10% (wt/wt)of the cross-linkedhydroxypropylated amylopectin, and 1% to 10% (wt/wt) of thepre-gelatinized common starch. In one embodiment, the release modifyingagent comprises about 90% (wt/wt) of the high amylose starch, about 5%(wt/wt) of the cross-linked hydroxypropylated amylopectin, and about 5%(wt/wt) of the pre-gelatinized common starch. This is in accordance withBlend 4 (see Example 1).

EXAMPLES

Introduction

Starch-based excipients can be used for formulation of drugs, e.g. withthe intention of making such drugs long-acting or to have prolongedeffectiveness. Such excipients have the ability to control thedissolution of the API in the gastrointestinal environment e.g. to allowit to take place continuously over a period of at least 8 hours asbenefits certain drug types e.g. analgesics or CNS drugs.

The gelling properties of a starch-based excipient are dependent on theratio between two essential sub-components, namely amylopectin andamylose. To be useful as an excipient in ER tablets, a formulation mustbalance the ratio of amylopectin and amylose content to achieve a gelwith an effective viscosity as well as achieve an effective gellingspeed. The state of the art shows that starting material corn starchescontaining 50% amylose content or more (high amylose starches [HAS]) aremore useful in producing ER tablets than those with less than 50%amylose content.

With the above-noted shortcomings of CLHAS, tests were designed andconducted to determine whether blends of various starch ingredientscould match or exceed the performance of commercially availableconventional CLHAS used in commercially available pharmaceuticalformulations.

Example 1: Acetaminophen Dosage Form

Dosage Form Manufacture

A summary of the starch blends prepared (Test Blends) is found in Table1.

TABLE 1 Raw Test Test Test Blend Test Blend Material Blend 1 Blend 2 3 4HAS 60 69.5 75 90 CMAP 35 5 15 5 PGS 5 25.5 10 5

CMAP indicates a cross-linked modified amylopectin, in this case across-linked hydroxypropylated amylopectin. In these experiments,Ultra-Tex 4™ was used.

HAS indicates a high amylose starch. In these experiments, Hylon VII™was used.

PG indicates a pre-gelatinized common starch. In this case, Starch 1500™was used.

Acetaminophen was used as an API to evaluate the release modifyingproperties of the Test Blends in Table 1. Acetaminophen was selected asan API to provide a meaningful comparison between tablets made usingeach of the Test Blends and identical tablets manufactured with acommercially available conventional CLHAS (Contramid®), known to be partof a clinically validated bilayer tablet.

The Test Blend containing tablets, comprised an immediate release (IR)layer designed to achieve an early rapid release of acetaminophen andthereby an early onset of analgesia, and an extended release (ER) layercomprising one of the Test Blends designed to extend analgesia for up to12 hrs.

Control tablets, comprising an equal amount of Contramid® were alsomanufactured. The quantitative composition of the acetaminophenformulations is provided in Table 2 where the components of each layerare indicated.

TABLE 2 Raw material mg/tab % w/w IR Layer Components Acetaminophen 90%(as Compap*) 166.7 14.25 Microcrystalline Cellulose PH102 84.8 7.24Colloidal Silicon Dioxide 1.3 0.11 Sodium Stearyl Fumerate 3.9 0.34 FD&CAluminum Lake Blue N° 1 (13%) 0.1 0.01 Croscarmellose Sodium 5.2 0.45 CRLayer Components Acetaminophen 90% (as Compap*) 666.7 56.98Microcrystalline Cellulose PH102 41.6 3.55 HPMC K100 Premium-LVCR 38.13.26 HPMC K100M Premium-CR 25.4 2.17 Copovidone 27.2 2.33 ColloidalSilicon Dioxide 4.5 0.39 Sodium Stearyl Fumerate 13.6 1.16 Contramid ®or Novel Test Blend 90.8 7.76 Total: 1170.0 100.0

It is noted that Compap is a compressible form of acetaminophencomprising 90% acetaminophen along with other directly compressibleexcipients. Total acetaminophen content was 750 mg.

Tablets were manufactured by blending the raw material components of theIR and ER layers separately using a V blender. Separate ER blends weremade for each of the starch blends shown in Table 1 and for the control,Contramid containing blend. Each of the ER blends was then compressedwith IR blend using a bilayer tablet press to achieve the finalcompressed tablet. The press tooling used for manufacture of the tabletsincluded a score to allow easy breaking of the tablets. The compressedtablets were then coated with a non-functional aesthetic film prior todissolution testing in both intact and bisected form.

Testing

The tablets were assessed for their dissolution performance in bothintact and bisected forms. The dissolution method employed USP Type IIIapparatus at a rate of 20 dips per minute. The dissolution medium usedwas 50 mM potassium phosphate buffer pH 6.8 (250 mL) at a temperature of37° C.±0.5° C. Dissolution tests were conducted on 6 tablets sampling atvarious interval times over a 12-hour period to establish a fulldissolution profile. The acetaminophen concentrations in the varioussamples were assessed using RP-HPLC and UV detection.

The pharmacokinetic performance of the control tablets was assessed inhumans as part of a study to assess the safety and efficacy of thetablets. Briefly, 48 subjects undergoing impacted third molar extractionwere administered 2 tablets immediately after surgery. Three millilitreblood samples were collected by indwelling catheters before the dose(time 0), and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, 10, and 12hours after the dose. The acetaminophen concentration in each sample wasthen determined by specific bioassay. The following single-dosepharmacokinetic parameters for acetaminophen in plasma were thenestimated using non-compartmental methods: area under the plasmaconcentration-time curve to the last quantifiable concentration (AUC);area under the plasma concentration-time curve extrapolated to infinity(AUCINF); percentage of AUCINF obtained by extrapolation (% AUC, exp);maximum plasma concentration (CMAX); maximum time (TMAX); apparentterminal rate constant and half-life (T½).

Results

FIG. 1 shows in vitro dissolution performance of the control tabletswhich serves as a benchmark for subsequent in vitro tests.

FIG. 2 shows the mean plasma acetaminophen concentrations over time asgenerated by the control tablets. The biphasic nature of the in vitrodissolution profile is reflected in the in vivo pharmacokineticsgenerated by the tablets. The pharmacokinetic parameters calculated areshown in Table 3.

TABLE 3 Parameter Value Mean exposure (AUC) 74.433 μg · h/mL Mean(AUC_(INF)) 100.46 μg · h/mL Mean max plasma  9.889 μg/mL concentration(C_(max)) Absorption rate (T_(max))  3.331 hrs Mean apparent terminalrate  0.144 l/h constant Mean half-life (T_(1/2))  5.381 hrs

FIG. 3 shows the dissolution performance of tablets with ER layerscomprising one each of the Test Blends shown in Table 1.

These results show that, contrary to previous teachings, simple mixturesof the three starches constituting each of the blends in Table 1maintained the extended release characteristics of the ER layer.Cross-linking of amylose to amylose, amylose to amylopectin andamylopectin was not needed.

Further, blending the starch components shown in the differentproportions shown in Table 1 resulted in blends with different releasemodifying properties with some generating ER layers that releasedacetaminophen more slowly than was achieved by the control and some thatreleased acetaminophen more rapidly. Simple mixing is therefore able togenerate a more versatile release modifying excipient than Contramid,which as a conventional CLHAS has a fixed proportion of amylose toamylopectin and where amylose-amylose, amylose-amylopectin andamylopectin-amylopectin cross links exist.

Contrary to previous teachings simple blends of the three starchesconstituting each of the blends in Table 1 have been shown to maintainthe extended release characteristics of the ER layer. Cross-linking ofamylose to amylose, and of amylose to amylopectin, was not needed.

Blending the three starches in different proportions resulted indifferent extended release properties some generating ER layers thatreleased acetaminophen more slowly than was achieved by Contramid® andsome that released acetaminophen more rapidly. Simple mixing istherefore able to generate a more versatile excipient than Contramid®.

Test Blend 3 generated an f2 similarity factor above 50 (see FIG. 3). Anf2 factor above 50 indicates that the tablets, manufactured using thenovel triple blend will be bio-equivalent in vivo to those manufacturedwith Contramid® i.e. that they will generate the data bio-equivalent tothose shown in FIG. 2 and Table 3.

FIG. 4 demonstrates in vitro dissolution performance of acetaminophentablets comprising equal amounts of either Contramid or Test Blend 3 intheir ER layers. The same degree of extended release was achievedwhether Test Blend 3 or Contramid was used. The Test Blend 3 compositionof HAS:CMAP:PGS of 75:15:10 thus generated an ER layer which bestmatched the performance of the ER layer comprising Contramid®

A conventional CLHAS, such as Contramid®, has the ability to retain theextended release characteristics of an ER tablet despite the tabletbeing broken. This feature is valuable since it protects patients fromthe uncontrolled, sudden release of drug (dose dumping) that will occurwhen tablets comprising conventional ER tablet technologies are brokenand the subsequent potentially dangerous increases in API concentrationin the blood that occur as a consequence. It is important therefore thatany replacement for a conventional CLHAS such as Contramid® retains thisfeature.

The dissolution performance of the tablets shown in FIG. 4 in both theintact and bisected form, was therefore assessed using the dissolutionmethod described above. FIG. 5 depicts these results. As is evident,intact and bisected tablets comprising Test Blend 3 displayed the samedissolution profiles with an f2 of 90. The release rate of acetaminophenwas unchanged by breaking the tablet. Results for the half tablets weredose normalized. No dose dumping occurs.

Example 2: Trazodone 24-hour Dosage Form

The performance of the 75:15:10 blend was validated by using it toreplace Contramid® in an existing Contramid® ER tablet (Contramid®Trazodone 24 hr ER tablets as described in U.S. Pat. No. 8,414,919).These tablets were single layer scored tablets made by blending and thencompression of the raw materials shown in Table 4.

TABLE 4 Raw material mg/tab % w/w Trazodone HCl 300.0 49.0 HPMC K100M100.0 16.3 Silicon dioxide 3.0 0.5 Sodium stearyl fumerate 9.0 1.5Contramid ® or Starch Blend 200 32.7 75:15:10 Total: 612.0 100.0

Here, the “Starch Blend 75:15:10” corresponds to Blend 3 described inTable 1. The dissolution performance of the both tablet formulations wasassessed using USP Type II (Paddle) apparatus operating at a rate of 50rpm. The dissolution medium used was water (900 mL) at a temperature of37° C.±0.5° C. Dissolution tests were conducted on 6 tablets sampling atvarious interval times over a 24 hr period to establish a fulldissolution profile. The trazodone concentrations in the various sampleswere assessed using RP-HPLC and UV detection.

FIG. 6 depicts in vitro release of trazodone from dosage formscomprising and equal amount of either Test Blend 3 or Contramid®.Tablets made with either Contramid® or Test Blend 3 displayed the samein vitro dissolution performance, the latter generating an f2 value of80 versus the Contramid® version. The starch blend was therefore able toreplace Contramid® in this tablet formulation.

Example 3: Tramadol 24-Hour Dosage Form

The performance of the 75:15:10 blend was further validated by againusing it to replace Contramid® in a novel ER tramadol hydrochloridetablet designed to display 24 hr dissolution performance. These tabletswere single layer scored tablets made by blending and then compressionof the raw materials shown in Table 5.

TABLE 5 Raw material mg/tab % w/w TRAMADOL HCL 300.00 27.264% StarchBlend 75:15:10 (Blend 3) 118.55 10.774% Kollidon SR 443.39 40.296%Xanthan gum 80 mesh 221.71 20.149% Hydrogenated vegetable oil 9.82 0.892% Colloidal Silicon Dioxide 1.96  0.178% Magnesium stearate 4.91 0.446% Total: 1100.34    100%

The dissolution performance of these tablets was tested replacing the pH6.8 dissolution medium with the following:

pH 1.2 dilute hydrochloric acid,

pH 4.5 50 mM phosphate buffer,

40% ethanol in pH 6.8, phosphate buffer.

FIG. 7 shows the dissolution rate in pH 1.2, pH 4.5, pH 6.8 and in 40%ethanol (*) (the latter condition selected to mimic administration withalcoholic beverages). Evident is that the novel starch containingtablets provide dissolution rate for API that are independent of pH frompH 1.2 to pH 6.8, conditions relevant to those found in thegastrointestinal tract of humans. Also evident is that, unlike filmbased ER tablet technologies which dose dump under these conditions, therelease rate of the tablets in 40% ethanol is lower than that in purelyaqueous media. This is feature protects patients from the harmfuleffects of dose dumping but also reduces the impact of enhanced drugabsorption that can occur when API such as tramadol are administeredwith alcohol.

A further tramadol dosage form was made by blending and compressing theraw materials show in Table 6.

TABLE 6 Raw material mg/tab % w/w TRAMADOL HCL 300.00 27.518% StarchBlend 75:15:10 (Blend 3) 118.55 10.874% Xanthan gum 80 mesh 664.7660.977% Colloidal Silicon Dioxide 1.96  0.180% Magnesium stearate 4.91 0.450% Total: 1090.19    100%

The dosage form was also scored for subdivision into halves.

FIG. 8 shows in vitro dissolution profiles of the subdivided halves ofthis formulation (bottom curve) as versus a comparable controlledrelease tramadol formulation (Tridural®) comprising Contramid. Profileswere measured in a Type I USP Dissolution Apparatus in 900 mL pH 6.8phosphate buffer at 100 rpm. Dose dumping for the latter is evident,with Tridural® displaying a significantly accelerated rate of release,and releasing almost 90% of it tramadol by four hours, as compared toabout 40% release of tramadol for the above-described formulation (Table6) comprising the novel release-modifying excipient (Test Blend 3). TestBlend 3 containing tablets displayed a release rate that issubstantially the same, whether intact or broken. In this sense thenovel excipient outperforms Contramid®.

Discussion of Examples

Extended release dosage forms are valuable to the patient due to theirconvenience and because they promote compliance.

Previously scientific literature taught that only cross linked highamylose starches comprising cross linked chemically modifiedamylose-amylose molecules, cross-linked chemically modifiedamylose-amylopectin molecules, and cross linked chemically modifiedamylopectin-amylopectin molecules, could be used in the manufacture ofextended release dosage forms. Contrary to this, it has been shownherein that a blend of cross linked and chemically modified amylopectin,physically and intimately mixed with a non-cross linked high amylosestarch and a pregelatinized starch can effectively reproduce theperformance of a conventional CLHAS (Contramid®) when included inextended release tablets tested both in vitro and in vivo. Further, ithas been confirmed that the safer use features imparted by conventionalCLHAS (as described in U.S. Pat. No. 8,414,919)—e.g., allowing extendedrelease dosage forms to be broken without dose dumping, and theavoidance of dose-dumping in the presence of alcohol—can also bemaintained by such a blend.

Previously, it was believed that conventional CLHAS would allow tabletbreaking. Here, it has been shown, while this is the case for the novelblend, it is not the case for the conventional CLHAS, Contramid. The newblend outperformed Tridural®, a Contramid®-containing tramadolformulation for dose dumping.

In addition it has been demonstrated that by varying the ratio of thethree starches included in the blend, the extended release properties ofthe novel starch drug release modifying excipient can be changed,thereby allowing greater versatility in modifying release delivery of awider range of APIs. The fact that the materials used to prepare theblend can be purchased from a number of suppliers, decreases thelikelihood of supply issues, while ensuring price competition and areduction in cost of goods that may be passed on to the patient.

Finally it has been demonstrated that tablet formulations comprising thenovel blends provide dissolution performance that is independent of pH,largely maintained following subdivision, and which can reduce therelease rate of API in the presence of ethanol. Unlike film based ERdosage form technologies which may dose dump under these conditions, thenovel blended controlled-release modifying release excipient provides anextra level of protection to the patient and peace of mind to thehealthcare provider.

In the preceding description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe embodiments. However, it will be apparent to one skilled in the artthat these specific details are not required. In other instances,well-known electrical structures and circuits are shown in block diagramform in order not to obscure the understanding. For example, specificdetails are not provided as to whether the embodiments described hereinare implemented as a software routine, hardware circuit, firmware, or acombination thereof.

The above-described embodiments are intended to be examples only.Alterations, modifications and variations can be effected to theparticular embodiments by those of skill in the art. The scope of theclaims should not be limited by the particular embodiments set forthherein, but should be construed in a manner consistent with thespecification as a whole.

REFERENCES

1. Dumoulin Y. U.S. Pat. No. 5,807,575

2. Lenaerts V. U.S. Pat. No. 6,607,748 B1

3. Moore, J. W. and H. H. Flanner, 1996, “Mathematical Comparison ofDissolution Profiles,” Pharmaceutical Technology, 20 (6):64-74.

4. Tramadol hydrochloride. Full Prescribing informationhttps://www.accessdata.fda.gov/drugsatfda_docs/label/2009/020281s032s0331lbl.pdf

5. Acetaminophen Dosage https://www.drugs.com/dosage/acetaminophen.html

6. deVane C. J Clin Psychiatry. 2003; 64 Suppl. 18:14-9

7. Klein E. J Clin Psychiatry. 2002; 463 Suppl 14:27-33.

8. Michelson E. Clin Cardiol. 1991 December; 14(12):947-50.

9. Nicholson B. Pain Pract. 2009 January-February; 9(1):71-81

10. Navarro V. Adv Ther. 2010 November; 27(11):785-95.

11. Porter C. Drug Development and Industrial Pharmacy Volume 15,1989-Issue 10

12. Thakral S. Expert Opinion on Drug Delivery Volume 10, 2013—Issue 1

13. Rosiaux Y J. Control Release. 2013 Jul. 10; 169 (1-2):1-9.

14. Bhardway T. Drug Development and Industrial Pharmacy Volume 26,2000-Issue 10

16. Singh K. Journal of Drug Delivery & Therapeutics; 2013, 3(5),156-162

17. Hiremath P. AAPS PharmSciTech. 2008; 9(4):1171-1178.

18. U.S. Pat. No. 8,414,919.

All references referred to herein are incorporated by reference in theirentireties.

What is claimed is:
 1. A modified release pharmaceutical dosage formcomprising: a CNS active drug, and a release modifying excipient, therelease modifying excipient comprising: 70-80% (wt/wt) of anon-cross-linked high amylose starch, 10-20% (wt/wt) of a cross-linkedhydroxypropylated amylopectin, and 5-15% (wt/wt) of a pre-gelatinizedcommon starch, wherein the modified release pharmaceutical dosage formis breakable into two or more pieces.
 2. The modified releasepharmaceutical dosage form of claim 1, wherein the CNS active drugcomprises an analgesic, an antidepressant, or an anxiolytic drug.
 3. Themodified release pharmaceutical dosage form of claim 1, wherein the CNSactive drug comprises tramadol hydrochloride, trazodone hydrochloride,or a pharmaceutically acceptable salts thereof.
 4. The modified releasepharmaceutical dosage form of claim 3, wherein the CNS active drugcomprises the tramadol hydrochloride or the pharmaceutically acceptablesalt thereof.
 5. The modified release pharmaceutical dosage form ofclaim 4, which is scored.
 6. The modified release pharmaceutical dosageform of claim 4, which, upon subdivision, maintains substantially thesame release profile for the tramadol or the pharmaceutically acceptablesalt thereof as the intact dosage form.
 7. The modified releasepharmaceutical dosage form of claim 4, which comprises the tramadol orthe pharmaceutically acceptable salt thereof in an amount of 50 mg, or100 mg, or 150 mg, or 200 mg, or 300 mg.
 8. The modified releasepharmaceutical dosage form of claim 4, comprising 13 to 56% (wt/wt) ofthe tramadol or the pharmaceutically acceptable salt thereof, and 5 to20% (wt/wt) combined weight of the high amylose starch, the cross-linkedhydroxypropylated amylopectin, and the pre-gelatinized common starch. 9.The modified release pharmaceutical dosage form of claim 4, wherein,upon subdivision, the two subdivided portions release less than 50% ofthe tramadol or the pharmaceutically acceptable salt thereof at fourhours, as measured in a USP Type III Apparatus in 900 mL of pH 6.8phosphate buffer at 100 rpm at a temperature of 37° C.
 10. The modifiedrelease pharmaceutical dosage form of claim 3, wherein the CNS activedrug comprises the trazodone hydrochloride or the pharmaceuticallyacceptable salt thereof.
 11. The modified release pharmaceutical dosageform of claim 10, which is scored.
 12. The modified releasepharmaceutical dosage form of claim 10, which, upon subdivision,maintains substantially the same release profile for the tramadol or thepharmaceutically acceptable salt thereof as the intact dosage form. 13.The modified release pharmaceutical dosage form of claim 10, whichcomprises the trazadone or the pharmaceutically acceptable salt thereofin an amount of 75 mg, 150 mg or 300 mg.
 14. The modified releasepharmaceutical dosage form of claim 10, comprising 25 to 75% (wt/wt) ofthe trazodone or the pharmaceutically acceptable salt thereof, and 15 to60% (wt/wt) combined weight of the high amylose starch, the cross-linkedhydroxypropylated amylopectin, and the pre-gelatinized common starch.15. The modified release pharmaceutical dosage form of claim 10,comprising 45 to 55% (wt/wt) of the trazodone or the pharmaceuticallyacceptable salt thereof, and 27 to 38% (wt/wt) combined weight of thehigh amylose starch, the cross-linked hydroxypropylated amylopectin, andthe pre-gelatinized common starch.
 16. The modified releasepharmaceutical dosage form of claim 10, wherein, upon subdivision, thetwo subdivided portions release less than 50% of the trazodone or thepharmaceutically acceptable salt thereof at four hours, as measured in aUSP Type III Apparatus in 900 mL of pH 6.8 phosphate buffer at 100 rpmat a temperature of 37° C.